The encounter took place Saturday morning when Harper was finished speaking to the group of leaders. Putin stuck out his hand first and Harper returned the gesture to complete the handshake and the words of wisdom.

Summit leaders planned to further discuss the matter in Ukraine Saturday ahead of the European Union’s decision on further sanctioning Russia over the Ukraine conflict.

President Obama said that the United States was a leading voice in opposing Russian aggression in Ukraine, which he described as "a threat to the world."

He referred to the shooting down on July 17 of a Malaysia Airlines jet by a missile suspected to have been fired by Russian-backed rebels in eastern Ukraine with the loss of 298 lives, including 38 Australian citizens and residents.

"As your ally and friend, America shares the grief of these Australian families and we share the determination of your nation for justice and accountability," Obama said.

Russia must use its influence on the rebels to ensure they comply with the Minsk agreement, stop the flow of weapons and troops from Russia and withdraw Russian troops already in Ukraine, EU president Herman von Rompuy said.

"Russia has still the opportunity to fulfill its Minsk agreements and chose the path of de-escalation, which could allow sanctions to be rolled back," he said. "If it does not do so however, we are ready to consider additional action."